Steinhart 2002.

Methods	Randomized, placebo controlled with blinded investigators Intention to treat not performed Eight week trial
Participants	Patients aged 14 years or older with active CD (CDAI 200‐400) (N = 134)
Interventions	Patients were randomised to receive oral ciprofloxacin 500 mg BID and oral metronidazole 500 mg BID (n = 66) or oral placebo (n = 68) All patients received oral budesonide 9 mg once daily
Outcomes	Primary outcome:The number of patients in remission at week 8, defined by CDAI < 150 Secondary outcomes: The mean changes in scores on the CDAI, quality of life, and adverse drug reactions
Notes	Patients were 14 years and older
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer generated randomisation
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Investigators and participants were blinded to treatment assignment Double blind: identical placebo
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Investigators were unaware of treatment assignments
Incomplete outcome data (attrition bias) All outcomes	Low risk	Sixteen patients in the placebo group and 22 patients in the antibiotic group did not complete the treatment course
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported
Other bias	Low risk	No other apparent sources of bias